1. Field of the Invention
The present invention relates to a photosensitive tabular member suction mechanism and an image recording device.
2. Description of the Related Art
Among image recording devices where a photosensitive tabular member is placed on a stage and a desired pattern is recorded, there is a device of a configuration where plural suction holes are formed in a placement surface of the stage and the photosensitive tabular member placed on the placement surface is sucked and retained by negative pressure.
However, because there is so-called air leakage from the periphery of the photosensitive tabular member placed on the placement surface, devices such as a larger vacuum pump and blower become necessary in order to obtain a sufficient suction force.
Also, in this configuration, the plural suction holes are dispersed in a wide range of the placement surface to match the maximum-size photosensitive tabular member of photosensitive tabular members of plural sizes that become the targets of image recording. Thus, in a case where a photosensitive tabular member of a smaller size is sucked, pressure inside the sucking stage rises (i.e., reduction in negative pressure), and there is the potential for a sufficient suction force to not be obtained because the suction holes positioned at the outer sides of the photosensitive tabular member are not blocked by the photosensitive tabular member and air flows in from these.
In order to eliminate this drawback, a method is conceivable where the unused suction holes at the outer side regions of the photosensitive tabular member are covered (blocked) with a film. However, with this method, it is necessary to prepare and adhere, to the placement surface, films of shapes corresponding to each of the different sizes of the photosensitive tabular materials, which is troublesome.
With respect thereto, Japanese Patent Application Laid-Open Publication (JP-A) No. 6-345279 discloses an exposure device of a configuration where the inside of the stage is separated into plural suction areas to match the sizes of substrates that are the photosensitive tabular members, tubes are divided, suction valves are switched to match the substrate size, and the substrate is sucked in a suction area of a size smaller than that of the substrate. However, with this configuration, the internal structure of the stage becomes complicated and the accommodatable substrate sizes are limited.
JP-A No. 3-73289 discloses a suction/retention mechanism configured so that the suction holes not covered by the substrate are closed by the deformation of a diaphragm or cylindrical elastic body. However, with this configuration, it is necessary to cause the suction force to act in order to also close the unused suction holes because the device is configured to cause the diaphragm or cylindrical elastic body to deform with the negative pressure inside the stage, and the suction force resulting from the negative pressure inside the stage cannot be used effectively.